Mtc key management for sending key from network to ue

Abstract

A root key (K_iwf) is derived at a network and sent to MTC UE ( 10 ). The K_iwf is used for deriving subkeys for protecting communication between MTC UE ( 10 ) and MTC-IWF ( 20 ). In a case where HSS ( 30 ) derives the K_iwf, HSS ( 30 ) send to MTC-IWF ( 20 ) the K_iwf in a new message (Update Subscriber Information). In a case where MME ( 40 ) derives the K_iwf, MME ( 40 ) sends the K_iwf through HSS ( 30 ) or directly to MTC-IWF ( 20 ). MTC-IWF ( 20 ) can derive the K_iwf itself. The K_iwf is sent through MME ( 40 ) to MTC UE ( 10 ) by use of a NAS SMC or Attach Accept message, or sent from MTC-IWF ( 20 ) directly to MTC UE ( 10 ). In a case where the K_iwf is sent from MME ( 40 ), MME ( 40 ) receives the K_iwf from HSS ( 30 ) in an Authentication Data Response message, or from MTC-IWF ( 20 ) directly.

1 . A first network node comprising:
 at least one processor; and   at least one memory coupled to the at least one processor, the at least one memory storing instructions that when executed by the at least one processor, cause the at least one processor to:   receive, from a User Equipment (UE), a first message including capability information indicating that the UE is enabled for a service related to Machine Type Communication (MTC),   send a second message to the UE, wherein the UE derives an encryption key,   receive, from a third network node, a third message including key information related to derivation of a first key,   derive the first key based on the key information, and   send a fourth message including the first key to a second network node that derives the encryption key from the first key, wherein the second network node decrypts, by using the encryption key, messages passed between the UE and the second network node via the first network node.   
     
     
         2 . A method of a first network node, the method comprising:
 receiving, from a User Equipment (UE), a first message including capability information indicating that the UE is enabled for a service related to Machine Type Communication (MTC);   sending a second message to the UE, wherein the UE derives an encryption key;   receiving, from a third network node, a third message including key information related to derivation of a first key;   deriving the first key based on the key information; and   sending a fourth message including the first key to a second network node that derives the encryption key from the first key, wherein the second network node decrypts, by using the encryption key, messages passed between the UE and the second network node via the first network node.   
     
     
         3 . A second network node comprising:
 at least one processor; and   at least one memory coupled to the at least one processor, the at least one memory storing instructions that when executed by the at least one processor, cause the at least one processor to:   receive a first key from a first network node, wherein the first network node receives, from a User Equipment (UE), a message including capability information indicating that the UE is enabled for a service related to Machine Type Communication (MTC),   derive an encryption key from the first key, and   decrypt, by using the encryption key, messages passed between the UE and the second network node via the first network node.   
     
     
         4 . A method of a second network node, the method comprising:
 receiving a first key from a first network node, wherein the first network node receives, from a User Equipment (UE), a message including capability information indicating that the UE is enabled for a service related to Machine Type Communication (MTC);   deriving an encryption key from the first key; and   decrypting, by using the encryption key, messages passed between the UE and the second network node via the first network node.   
     
     
         5 . A User Equipment (UE) comprising:
 at least one processor; and   at least one memory coupled to the at least one processor, the at least one memory storing instructions that when executed by the at least one processor, cause the at least one processor to:   send, to a first network node, a first message including capability information indicating that the UE is enabled for a service related to Machine Type Communication (MTC),   receive a second message from the first network node,   derive an encryption key based on receipt of the second message, and   encrypt, using the encryption key, messages passed between the UE and a second network node via the first network node.   
     
     
         6 . A method of a User Equipment (UE), the method comprising:
 sending, to a first network node, a first message including capability information indicating that the UE is enabled for a service related to Machine Type Communication (MTC);   receiving a second message from the first network node;   deriving an encryption key based on receipt of the second message; and   encrypting, using the encryption key, messages passed between the UE and a second network node via the first network node.